title: Treatment of hip dysplasia in patients with mucopolysaccharidosis type I after hematopoietic stem cell transplantation: results of an international consensus procedure.
abstract: BACKGROUND
  Mucopolysaccharidosis type I (MPS-I) is a lysosomal storage disorder characterized by progressive multi-organ disease. The standard of care for patients with the severe phenotype (Hurler syndrome, MPS I-H) is early hematopoietic stem cell transplantation (HSCT). However, skeletal disease, including hip dysplasia, is almost invariably present in MPS I-H, and appears to be particularly unresponsive to HSCT. Hip dysplasia may lead to pain and loss of ambulation, at least in a subset of patients, if left untreated. However, there is a lack of evidence to guide the development of clinical guidelines for the follow-up and treatment of hip dysplasia in patients with MPS I-H. Therefore, an international Delphi consensus procedure was initiated to construct consensus-based clinical practice guidelines in the absence of available evidence.
  
  
  METHODS
  A literature review was conducted, and publications were graded according to their level of evidence. For the development of consensus guidelines, eight metabolic pediatricians and nine orthopedic surgeons with experience in the care of MPS I patients were invited to participate. Eleven case histories were assessed in two written rounds. For each case, the experts were asked if they would perform surgery, and they were asked to provide information on the aspects deemed essential or complicating in the decision-making process. In a subsequent face-to-face meeting, the results were presented and discussed. Draft consensus statements were discussed and adjusted until consensus was reached.
  
  
  RESULTS
  Consensus was reached on seven statements. The panel concluded that early corrective surgery for MPS I-H patients with hip dysplasia should be considered. However, there was no full consensus as to whether such a procedure should be offered to all patients with hip dysplasia to prevent complications or whether a more conservative approach with surgical intervention only in those patients who develop clinically relevant symptoms due to the hip dysplasia is warranted.
  
  
  CONCLUSIONS
  This international consensus procedure led to the construction of clinical practice guidelines for hip dysplasia in transplanted MPS I-H patients. Early corrective surgery should be considered, but further research is needed to establish its efficacy and role in the treatment of hip dysplasia as seen in MPS I.
authors.affiliation: Department of Pediatrics and Lysosome Center 'Sphinx', Academic Medical Center, University of Amsterdam, H7-270, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. f.a.wijburg@amc.uva.nl.
authors.forename: Eveline J
authors.initials: EJ
authors.lastname: Langereis
authors.forename: Andrea
authors.initials: A
authors.lastname: Borgo
authors.forename: Ellen
authors.initials: E
authors.lastname: Crushell
authors.forename: Paul R
authors.initials: PR
authors.lastname: Harmatz
authors.forename: Peter M
authors.initials: PM
authors.lastname: van Hasselt
authors.forename: Simon A
authors.initials: SA
authors.lastname: Jones
authors.forename: Paula M
authors.initials: PM
authors.lastname: Kelly
authors.forename: Christina
authors.initials: C
authors.lastname: Lampe
authors.forename: Johanna H
authors.initials: JH
authors.lastname: van der Lee
authors.forename: Thierry
authors.initials: T
authors.lastname: Odent
authors.forename: Ralph
authors.initials: R
authors.lastname: Sakkers
authors.forename: Maurizio
authors.initials: M
authors.lastname: Scarpa
authors.forename: Matthias U
authors.initials: MU
authors.lastname: Schafroth
authors.forename: Peter A
authors.initials: PA
authors.lastname: Struijs
authors.forename: Vassili
authors.initials: V
authors.lastname: Valayannopoulos
authors.forename: Klane K
authors.initials: KK
authors.lastname: White
authors.forename: Frits A
authors.initials: FA
authors.lastname: Wijburg
mesh_terms: D018380:Hematopoietic Stem Cell Transplantation; D006617:Hip Dislocation / Q000209:etiology* / Q000601:surgery; D006801:Humans; D008059:Mucopolysaccharidosis I / Q000150:complications / Q000628:therapy*